Improvement in sewing-machines



PATENm JUL 251871 Witnesses UNITED STATES` PATENT OFFICE.

THOMAS CRANE, OF FORT ATKINSON, WISCONSIN, ASSIGNOR- TO HIMSELF' ANDMELVIN A. JONES, OF SAME PLACE.

IMPROVEMENT IN SEWING-MACHINES.

Specification forming p'art of Letters Patent No. 117,262, dated July25, 1871.

To all whom it may concern:

Be it known that I, THOMAS CRANE, of Fort Atkinson, in the county of Jeii'erson and State of Wisconsin, have invented a ne'w and usefulImprovement in Sewing-Machines; and I do hereby declare the following tobe a full, clear, and exact description thereof, which will enableothers skilled in the art to which my invention appertains to make anduse the same, reference being had to the accompanying drawing formingpart f this specification, in which- Figure l is a side elevation ot myinvention with a part of the frame broken olf, cutting a portion of themoving-part through the center. Fig. 2 is an end view of a portion ofthe Vsame detached therefrom. Fig. 3 is a vertical transverse sectionthrough the presser-bar, showing the moving parts thereof. Fig. 4 is anend view of the cam-wheel employed in giving motion to the moving partsof the machine. Fig. 5 is a cross-section of the same, showing thestirrup and rock-shaft employed in oscillating the shuttle-bar. Fig. 6is a-.side view of the same with the stirrup removed, showing thecamgroove by which the oscillating movement of the shuttlebar isproduced; and Fig. 7 is a top view of the shuttle enlarged, showing themanner of adjusting the springby which the proper tension of thread isobtained. Y

Similar letters of reference indicate corresponding parts in the severalfigures of the drawing.

The object of my invention is to provide a sewing-machine. themechanical parts of which are so arranged as to simplify the generalconstruction and operation of the same, and so that it will sew backwardor forward7 at the will of the operator, without readjustment or changeof stitch. The improvement consists, among other things, in securing acrank-shaft, operating the needle-bar, to and within a tubularoscillatory bar so arranged as to vibrate laterally simultaneously withthe rotating movement of the shaft, by which means the crank isuniformly at a center vertically with the needle-bar, thus imparting tothe same a positive vertical movement. It further consists in providing'the wheel or pulley ofthe crank-shaft with a cycloid cam-groove, withinwhich is fitted a semi-angular oscillating stirrup, to which is pivoteda rock-shaft communicating with the shuttle-bar, by which means areciprocal movement is imparted to said shuttle-bar by the combinedvibrating movement of the crank-shaft and oscillating movement of thestirrup produced by the rotary movement of the cam, thus moving theshuttle alternately with the needle by which the stitch is formed.

In the accompanying drawing, A represents the frame of the machine,which may be as shown, or of any known form that will receive the movingparts, and is secured to the table-top in the usual manner. B is avertical guide-spindle, which is firmly affixed to the forward end ofthe frame. C is a tubular needle-bar, which is fitted upon said spindlein a manner admitting' of a free and easy vertical movement. The lowerend of said needle-bar is provided with an aperture, into which theshank of the needle a is introduced, which is rmly secured therein by aset-screw, b, passing through the side of the bar. I construct the lowerportion of said bar solid between the shank of the needle and the lowerend of the guide-spindle, thusadmitting the introduction of oil intosaid bar without the liability of its dripping upon the fabric. D is atubular triangular bar, which is pivoted at its upper and lower end tothe frame of the machine in a manner securing the same rigid vertically,but so arranged as to admit of an easy lateral reciprocal movement. E isthe shaft giving motion to the neeclle-bar,v'l1ich is loosely fittedwithin said bar D, and so arranged as to rotate therein. The forward endof said shaft is made less in diameter, and is bent or slightly curvedsufficient to form an eccentric or crank, the end of which is providedwith an aperture or socket, into which is loosely fitted a pivot, d,affixed to the upper end ofthe needle-bar. Firmly secured upon the rearend of said shaft is a sleeve, F, upon which is loosely fitted a pulley,G, which is provided externally with an annular groove, c, that receivesthe belt from the driving-wheel, not shown in the drawing. I provide theinner end of said sleeve with a ange, a portion of which is cut away,forming a clutch which is loosely itted within a corresponding recess,g, cut on the inner end of pulley G. Said recess is provided with astop-clutch, h, so arranged as to allow the pulley to rotate partiallyaround upon said sleeve, the object of which is to reverse the entiremoving parts of the machine, thus allowing the fabric to be stitched inabackward direction and preserving the corresponding stitch. I providepulley G with an annular cycloid cam-groove, H, within which is looselyfitted a semi-annular stirrup, I. To the upper end of said stirrup ispivoted externally a like stirrup, J, the lower portion of which isfirmly afxed to the upper end of a vertical rock-shaft, K, and is soarranged as to allow said stirrup I a slight oscillating movementtherein. The lower end of said shaft K is firmly aflixed to the rear endof the shuttle-bar L, and is secured within an outward-projectin gportion of the lower end of bar D, and is so arranged as to admit of aslight reciprocal rotary movement. Thus, as said pulley G is rotated,together with the oscillating movement of bar D produced by the rotatingmovement of shaft E, a reciprocal movement is imparted to theshuttle-bar. M is the feed-bar, which is pivoted at its forward end tothe lower side of the platform, and its rear'en d loosely litted uponthe lower end of lever N. The upper end of said lever is pivotedeccentrically to shaft E, and is provided at its lower end with ascrewthreaded nut, upon which the end of said feedbar is supported, thusallowing said bar to be raised or lowered, by which the feed is adjustedfor thick or thin fabric. Upon the lower end of said lever, and aroundthe same above the feedbar, is a spiral spring, m, so arranged as torest uponv its end, by which the same is secured in proper adjustment.Loosely fitted upon said lever is a sleeve, O, which is secured within avertical slot or mortise in the end of the frame, and is so arranged asto admit of a slight rocking movement, thus forming the fulcrum of saidlever, by which an elliptical reciprocal movement is imparted to thefeed-bar by the rotating movement of shaft E. Said sleeve is so fittedwithin the slot as to admit of being secured at and proper adjustedheight, thus increasing or diminishing the stroke ofthe feed-bar, bywhich mea-ns the graduated length of stitch is obtained. I) is thetake-up bar, which is loosely pivoted to the end of the frame, and Q thetake-up spring, firmly affixed thereto. P is an adjustable tubularguide-bar, which is fitted within a pivot affixed to the frame. Thethread from the spool is passed around and through said bar, thenceupward through the end of bar l and over the end of spring Q, thencedownward in a stra-ight line to the needle, the object of which is tosecure the proper tension of the thread without lateral friction of thesame. It is a tubular presser-bar, which is firmly secured to the frameby a screw-threaded bolt, n, passing into the upper end of the same. Thelower end of said bar is provided with a -vertical groove, within whichis iitted the shank of the presser-foot S. Aftixed to the upper end ofsaid shank is a vertical spindle, p, around which is ysecured a spiralspring, fr, by which the proper pressure is obtained upon the fabric.Firm 1y attached to the shank of said presser-foot is a set-screw, t,which is so arranged as to move freely within a vertical slot, s, cut inthe lower end of said bar. The upper end of said slot is provided with arecess, into which the head of said screw is admitted, said shank beingso ar 1anged as to admit of a slight vibrating movement to allow thesame, by which means said presser-foot is secured from and above thefabric. I provide the shuttle T with a curved spring, U, one end. ofwhich is rmly affixed thereto. To the opposite or curved end of saidspring is attached a lug, t, within which is secured a set-screw, W, soarranged as to come in contact with and against the inner side of theshuttle. The upper edge of said spring is provided at or near its centerwith a groove or slot cut across the same, through which the thread fromthe bobbin passes, the thread passing thence downward by the side ofsaid spring and through an aperture in the side of the shuttle; thus, assaid screw is adjusted, the spring is pressed against the thread, bywhich means the proper tension is obtained.

In operating my invention, power is applied to the treadle, which iscommunicated to pulley G of shaft E in the usual manner, giving to saidshaft a rotating movement, by which all the moving parts of the machineare made to perform their necessary function.

Having thus described the nature and object of my invention, what Iclaim as new, and desire to secure by Letters Patent, is-

l. A sewing-mechanism, composed of an eyepointed needle receiving itsmotion from a crank coupled directly to the needle-bar, a self-adjustingcam-pulley upon the crank-shaft, and an oscillating bar carrying thecrank-shaft, substantially as described, the combined action of whichgoverns the feed, shuttle, and needle movements, in sewing the same formof stitch forward and backward, by reversing the motion ofthe machine,substantially as specified.

2. The crank-shaft E, when so arranged as to vibrate laterallysimultaneously with a rotary movement of the same, whereby a verticalmovement is imparted to the needle-bar, substantially as described.

3. The combination of the crank-shaft E, vibrating' bar D, cam-pulley G,and rock-shaft K, the whole arranged to operate together, whereby areciprocal movement is imparted to the shuttle-bar, substantially asdescribed.

4. The combination of pulley Gr, stirrups I and J, rock-shaft K,oscillating bar D, and shuttlebar L, theI whole arranged to operatetogether, whereby the requisite reciprocating movement is imparted tosaid shuttle-bar by the rocking movement of the shaft K jointly with theoscillating movement of bar D, substantially as and for the purposedescribed.

The above specification of my invention signed by me this 23d day ofNovember, 1870.

THOMAS CRANE.

Vitnesses:

G. H. FRos'r, N. H. SnERBURNE.

